potentially malignant disorders

Question 1

What is a potentially malignant lesion?

Answer 1

Altered tissue which cancer is more likely to form

Question 2

What is a potentially malignant disorder?

Answer 2

Generalised state with increased cancer risk

Question 3

Give 4 examples of potentially malignant systemic conditions

Answer 3

Lichen planus
Oral submucous fibrosis
Iron deficiency - anaemia can lead to atrophy of oral epithelium so barrier function is diminished
Tertiary syphilis - can form white patch on tongue

Question 4

Describe chronic hyperplastic candidosis

Answer 4

Caused by C. albicans
Commissures seen at the angles of the mouth
Found in smokers
Dysplasia may be present

Question 5

How is chronic hyperplastic candidosis treated?

Answer 5

Systemic antifungal - fluconazole capsules, 50mg once daily for 14 days
Biopsy
Stop smoking
Observe

Question 6

Where do most oral carcinomas in the UK arise from?

Answer 6

Clinically normal mucosa

Question 7

How much more likely is leukoplakia to progress to cancer than clinically normal mucousa?

Answer 7

50 to 100 times

Question 8

What are the clinical predictors of malignancy in leukoplakia?

Answer 8

Age - older more likely
Gender - differs from country
Site - buccal mucosa is low risk, floor of mouth and tongue is high risk
Clinical appearance - if homogenous and smooth then less likely, non-homogenous, verrucous and ulcerated then mitre likely

Question 9

What are the histopathological predictors of malignant change?

Answer 9

Dysplasia
Atrophy
Candida infection
Biological markers eg - p53, HPV+ and HPV-

Question 10

What is dysplasia?

Answer 10

Disordered maturation (growth) in a tissue
A histopathological diagnosis, not clinical

Question 11

What is atypia?

Answer 11

Changes in cells

Question 12

What are the predictors for histopathology epithelial dysplasia?

Answer 12

Assess architectural changes then cytology
Architectural changes such as maturation (growth) and stratification (more layers)
Cytological abnormalities such as cellular atypia

Question 13

What is the WHO classification for grading of epithelial dysplasia?

Answer 13

Hyperplasia
Mild
Moderate
Severe
Carcinoma-in-situ

Question 14

How is staging and grading carried out?

Answer 14

Grading is done histopathologically
Staging is done clinically

Question 15

Describe basal hyperplasia

Answer 15

Increased number of basal cells, rest of epithelium is normal
Architecture - regular stratification, basal component is larger
No cellular atypia

Question 16

Describe mild dysplasia

Answer 16

Architectural changes in lower third
Cytology - mild atypia, pleomorphism and hyperchromatism

Question 17

What is pleomorphism?

Answer 17

Difference in size and shape of a cell

Question 18

What is hyperchromatism?

Answer 18

Darker staining of a cell due to more DNA present

Question 19

Describe moderate dysplasia?

Answer 19

Architecture changes extends into middle third
Cytology - moderate atypia - hyperchromatism and pleomorphism

Question 20

Describe severe dysplasia

Answer 20

Architecture changes extend into upper third
Cytology - severe atypia and numerous mitoses, abnormally high
- hyperchromatism and pleomorphism
- loss of polarity (lack of difference between different layers of cells)

Question 21

Describe a carcinoma-in-situ

Answer 21

A theoretical concept
Malignant but not invasive
Abnormal architecture - full thickness or almost full of viable cell layers
Pronounced cytological atypia - mitotic abnormalities frequent

Question 22

How may pathology be confirmed in the future?

Answer 22

Salivary biomarkers
Next generation sequencing
AI

Question 23

What common diagnostic tests are used for potentially malignant lesions?

Answer 23

Vital staining
Oral cytology
Optical imaging

Question 24

What are the 2 main factors of carcinogenesis?

Answer 24

Genetic
Environmental (carcinogens)

Question 25

What is the molecular basis of cancer?

Answer 25

Damage leads to altered gene expression which leads to altered cell function

Question 26

What is an oncogene?

Answer 26

A gene that has the potential to cause malignancy

Question 27

What are tumour suppressor genes?

Answer 27

Genes that regulate cell division

Question 28

What is miRNA?

Answer 28

Strands of RNA which can play a role in neoplastic transformation as they control the function of oncogenes and tumour suppressor genes

Question 29

How can oncogene inactivation/mutation lead to malignancy?

Answer 29

If 1 of a pair is inactivated/mutated, the others function will not be enough and the cell will become malignant

Question 30

How can tumour suppressor gene inactivation/mutation lead to malignancy?

Answer 30

Need both of a pair to be inactivated/mutated for the cell to become malignant
This is called Knudson’s ‘two hit’ hypothesis of carcinogenesis

Question 31

Give an example of a tumour suppressor gene and it’s role

Answer 31

Tp53 gene provides instructions for p53 protein

Question 32

Give an example of a viral component in oral cancer genetics?

Answer 32

HPV

Question 33

What are the 6 genetic changes of cancer?

Answer 33

Evading apoptosis
Self-sufficiency in growth signals
Insensitivity to anti-growth signals
Tissue invasion and metastasis
Limitless replication potential
Sustained angiogenesis

Question 34

What percentage of oral cancer is SCC?

Answer 34

95%

Question 35

What is cohesive front and non-cohesive front in cancer spread?

Answer 35

Cohesive front - cells are together and advance at the same time
Non-cohesive front - strong possibility of LN involvement even if no clinical signs of enlargement

Question 36

What are the 3 methods of oral cancer spread?

Answer 36

Local extension of disease
Lymphatic spread
Haematogenous spread

Question 37

How may oral cancer spread to bone?

Answer 37

Gaps in cortex in edentulous patients
PDL if patient is dentate

Question 38

Describe the subtypes of oral SCC?

Answer 38

Verrucous carcinoma - has the best outcome
Basaloid squamous - aggressive and associated with HPV
Spindle cell - aggressive and difficult to identify